Surface Atoms Dependence of ZnO Supported Ag@Pd Core@Shell Nanocatalysts in CO2 Hydrogenation to CH3OH

Carbon dioxide is the primary greenhouse gas and its emission has caused serious problems of climate change. So far, unremitting efforts are made to recycle of CO2 through its hydrogenation to liquid fuels such as CH3OH. Pd-ZnO based nanoarchitecture is believed to be one kind of ideal catalysts in CO2 hydrogenation. However, due to small palladium reserves on earth, enhancing the catalytic efficiency and selectivity of the palladium nanostructures with lowest loading remains to be a scientific challenge. In this work, three kinds of ZnO supported Ag@Pd core@shell, AgPd alloy and pure Pd nanocatalysts were controlled synthesized successfully. Benifiting from the electron rich Pd shell and the formation of PdZn phase in Ag@Pd-ZnO core@shell structure, its catalytic efficiency of per gram palladium exhibits 3.32 times higher than the Pd-ZnO nanostructure. Especially, electron transfer at the interfaces and the adsorption of the intermediate species significantly enhance catalytic selectivity of the Ag@Pd-ZnO core@shell structure. This work proposed a novel strategy to enhance the methanol yield during CO2 hydrogenation by the sophisticated tailoring of surface composition in noble catalysts.